How Much Is a New Furnace and AC Together? 2026 Cost Guide

An aging furnace can require more frequent repairs, create uneven heating, and consume more fuel as components wear. An aging air conditioner can cycle inefficiently, struggle to maintain the thermostat setting, and require repeated service.

When repair frequency increases or both systems approach approximately 15 years of operation, replacement can become worth comparing with continued repair costs.

A new furnace and central AC generally cost $5,000-$11,000 installed when existing ductwork remains usable. New ductwork can increase the project cost to approximately $7,000-$16,000.

Equipment capacity, efficiency, manufacturer, ductwork, labor, permits, electrical work, refrigerant connections, and installation conditions determine the final price. A professional load calculation and equipment inspection provide a more reliable replacement specification than home square footage alone.

Average Cost to Replace Furnace and AC Together

Replacing a furnace and central AC generally costs $5,000-$11,000 when existing ductwork remains usable. Projects requiring new ductwork generally cost approximately $7,000-$16,000, while HVAC replacement projects with additional equipment or installation work can reach approximately $18,500.

The final price depends on the equipment selected and the work required at the home. A typical replacement can include furnace removal, AC condenser removal, furnace installation, evaporator-coil installation, refrigerant connections, electrical connections, thermostat installation, duct connections, and system commissioning.

Equipment capacity also affects the quotation. A 2-ton AC provides 24,000 BTU/h of nominal cooling capacity, while a 4-ton AC provides 48,000 BTU/h. Furnace capacity uses BTU/h, whereas central AC capacity commonly uses tons. The contractor should calculate the home’s heating and cooling loads before selecting either capacity.

Real-World Cost Scenario

Consider a 2,000-square-foot, two-story home with a 15-year-old furnace, a 15-year-old AC, and usable existing ductwork. Using a planning range of approximately $3-$6 per square foot, the potential replacement range would be approximately $6,000-$12,000.

The square footage provides only a preliminary cost reference. The 15-year-old furnace establishes the heating equipment age, while the 15-year-old AC establishes the cooling equipment age. A contractor still needs to evaluate insulation, windows, air leakage, ductwork, equipment location, electrical requirements, and heating and cooling loads before preparing the final quotation.

Why Bundling Costs Less Than Separate Jobs

Replacing the furnace and AC together can reduce duplicated removal, setup, connection, and commissioning work. Contractors can coordinate furnace and condenser removal, furnace and evaporator-coil installation, refrigerant and duct connections, thermostat setup, and system testing within one project schedule.

The furnace blower distributes conditioned air at approximately 400 CFM per ton of cooling capacity through the supply ducts. The evaporator coil absorbs approximately 12,000 BTU of indoor heat per ton of rated cooling capacity during a cooling cycle. The outdoor condenser transfers that absorbed heat to the outside air through the refrigeration system.

Because these components operate as one connected system, replacing them during the same project can reduce repeated labor and installation steps. Homeowners should compare combined and separate quotations to determine the actual savings.

Matched System Components

A matched furnace-and-AC system connects equipment according to capacity, airflow, efficiency, refrigerant specifications, and controls. The contractor should verify compatibility before installation rather than selecting the furnace and AC independently.

For example, a 3-ton 16 SEER2 condenser requires an evaporator coil rated for approximately 1,200 CFM of airflow and a matched refrigerant charge to achieve its rated efficiency. Furnace capacity determines available heating output in BTU/h, while AC tonnage determines nominal cooling capacity.

The contractor also verifies blower airflow, refrigerant requirements, electrical connections, and thermostat compatibility to ensure the indoor and outdoor components operate as a matched system.

Installation and Permit Specifications

Local authorities determine HVAC permit requirements and fees. HVAC replacement permits can cost approximately $100-$250, while new HVAC installations involving ductwork can require approximately $250-$1,500 in permit fees.

HVAC installation labor generally costs $1,000-$3,000, equipment removal generally costs approximately $100-$200, and thermostat installation can cost approximately $140-$350. The final installation proposal should identify labor, permits, equipment removal, ductwork, electrical work, refrigerant connections, and commissioning.

What Affects the Price?

Furnace-and-AC replacement cost depends primarily on equipment capacity, efficiency, manufacturer, ductwork, labor, permits, and installation conditions. A contractor evaluates these factors together because changing one specification can affect other parts of the installation.

For example, AC capacity determines nominal cooling output, furnace capacity determines heating output, and ductwork determines how effectively conditioned air moves through the home. Equipment location also affects labor when technicians must modify electrical, gas, refrigerant, or duct connections.

The final quotation should separate equipment costs from labor and additional work. This allows homeowners to compare proposals using measurable specifications instead of comparing only the total price.

Unit Size and Tonnage

Central AC capacity uses tons, with one ton representing 12,000 BTU/h of nominal cooling capacity. A 2-ton AC therefore provides 24,000 BTU/h, while a 3-ton AC provides 36,000 BTU/h.

The contractor should use a heating and cooling load calculation to select equipment capacity. The calculation considers insulation, windows, climate, building orientation, air leakage, occupancy, and ductwork.

An oversized AC can cycle more frequently and reduce the time available for humidity removal. An undersized AC can operate for longer periods while struggling to maintain the thermostat setting. Correct sizing therefore affects comfort, operating performance, and equipment cycling.

Efficiency Ratings

SEER2, EER2, and AFUE provide measurable efficiency specifications for HVAC equipment. SEER2 measures seasonal cooling efficiency, EER2 measures cooling performance under specified test conditions, and AFUE measures furnace fuel-conversion efficiency.

A 96% AFUE furnace converts approximately 96% of fuel energy into usable heat. SEER2 provides a seasonal efficiency measurement for the air conditioner, while EER2 provides a cooling-efficiency measurement under defined operating conditions.

Homeowners should compare efficiency ratings with equipment price, expected operating hours, local climate, warranty coverage, and installation cost. The highest available rating does not automatically provide the lowest overall ownership cost.

Ductwork Condition

Ductwork distributes conditioned air between HVAC equipment and occupied rooms. Leaking, damaged, disconnected, or undersized ducts can reduce airflow and increase the work required during equipment replacement.

Current ductwork replacement pricing generally falls around $1,400-$5,600, while new ductwork installation can cost approximately $2,400-$6,600. Supply ducts deliver conditioned air to rooms, return ducts carry indoor air back to HVAC equipment, and duct insulation reduces heat transfer through duct surfaces.

A contractor should inspect duct connections, insulation, supply registers, return pathways, and airflow before including ductwork repairs or replacement in the proposal.

Brand and Equipment Model

Goodman, Carrier, Trane, and Lennox offer furnace and AC models with different capacities, efficiency ratings, controls, warranties, and configurations. The specific equipment model matters more than the manufacturer name alone.

A furnace model provides a defined heating capacity in BTU/h, an AC model provides a defined cooling capacity in tons, and an equipment model carries defined efficiency specifications such as SEER2 or AFUE. Homeowners should also compare compressor configuration, blower configuration, thermostat compatibility, equipment warranty, labor warranty, and installed price.

No single manufacturer provides the best equipment for every home. Installation quality, correct sizing, compatibility, warranty coverage, and total installed cost should remain part of the comparison.

Labor and Additional Work

HVAC installation labor generally costs $1,000-$3,000, with the final amount depending on equipment location, accessibility, ductwork modifications, electrical connections, gas connections, refrigerant work, and equipment removal.

Equipment removal generally costs approximately $100-$200, while thermostat installation can cost approximately $140-$350. Combined furnace-and-AC installation labor averages approximately $1,500 within the broader HVAC installation labor range.

A detailed quotation should identify labor separately from equipment, permits, ductwork, removal, accessories, and other installation requirements.

Replacing Furnace and AC Together vs. Separately

Replacing both systems together can make sense when the furnace and AC have similar ages, recurring repair requirements, declining efficiency, or compatibility concerns. A combined project can coordinate connected components that operate together, including the furnace blower, evaporator coil, condenser, thermostat, and ductwork.

A 15-year-old furnace represents equipment approaching a common replacement-planning age, while a 15-year-old AC represents a similar planning point for cooling equipment. Repair costs approaching 50% of replacement cost provide another reason to compare repair and replacement.

A homeowner with a 5-year-old furnace and 15-year-old AC may choose AC-only replacement if the furnace remains reliable and compatible. A homeowner with a 15-year-old furnace and 15-year-old AC may compare combined replacement against continued repair costs.

The furnace blower, evaporator coil, and outdoor condenser work together to deliver heating and cooling through the home’s duct system. Replacing these connected components together can reduce duplicated installation activities. A combined project also allows the contractor to verify airflow, refrigerant charge, and thermostat operation during the same commissioning process.

Equipment age, repair history, efficiency, compatibility, comfort performance, and replacement pricing should determine the replacement strategy.

Financing Options

HVAC financing allows homeowners to spread furnace-and-AC replacement costs across scheduled payments instead of paying the full project cost upfront. Financing terms vary by lender and offer, so homeowners should evaluate the complete repayment obligation.

A 60-month financing term at 7.9% APR on a $9,000 project produces approximately $182 in monthly payments. A $250 monthly payment for 60 months produces $15,000 in scheduled payments, while a $350 monthly payment for 36 months produces $12,600, before applicable fees or financing adjustments.

The interest rate determines borrowing cost, the loan term determines repayment duration, and the monthly payment determines recurring cash-flow requirements. Financing fees can also increase the total amount repaid beyond the original HVAC project price.

Homeowners should compare APR, financing fees, loan term, monthly payment, and total repayment. A lower monthly payment can result in higher total repayment when the financing term extends for a longer period.

Knowing how much to replace a furnace and air conditioner gives you a useful starting point, but your home’s actual requirements determine the final cost.

A professional HVAC evaluation can help determine the correct furnace capacity, AC tonnage, efficiency level, ductwork requirements, and installation scope.

Planning to replace your furnace and AC together? Learn more about our Furnace Replacement & AC Bundle services and explore your replacement options.